Banca de DEFESA: VASCO DE LIMA PINTO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : VASCO DE LIMA PINTO
DATE: 04/09/2023
TIME: 09:00
LOCAL: videoconferência
TITLE:

RENEWABLE HYDROCARBON PRODUCTION VIA THERMO-CATALYTIC PYROLYSIS OF BOVINE TALLOW USING MESOPOROUS METAL OXIDE CATALYSTS.

KEY WORDS:

Beef Tallow; MCM-41; Pyrolysis; Biohydrocarbons; Kinetic Study.

PAGES: 138
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Físico-Química
SPECIALTY: Cinética Química e Catálise
SUMMARY:

The need to explore new energy sources has escalated due to the issues stemming from the utilization of fossil fuels, such as acid rain, the greenhouse effect, and global warming. These concerns have significant societal implications, imperiling human survival and long-term sustainability. In this doctoral thesis, an investigation was conducted on mesoporous MCM-41 catalysts integrated with metallic oxides (cobalt, nickel, and molybdenum) to produce renewable hydrocarbons from bovine tallow. The raw material was procured from the Mossoró Industrial Slaughterhouse and subjected to physicochemical characterization. The synthesized catalysts were subjected to structural, chemical, and morphological analyses through X-ray Diffraction (XRD), X-ray Fluorescence (XRF), Fourier-Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Spectroscopy (EDS). These analyses verified the preservation of porous structures after the incorporation of metallic oxides. Activation energies of the catalysts were determined using the isoconversional methods proposed by Ozawa-Flinn-Wall (OFW) and Kissinger Akahira Sunose (KAS). This was based on thermogravimetric analyses of bovine tallow and its mixtures with the catalysts, employing heating rates (β) of 10, 20, and 30°C/min and conversion rates (α) of 5, 10, 20, 30, 40, 50, 60, 70, 80, and 90%. The catalysts synthesized in this study, according to both methods, demonstrated effectiveness in lowering the activation energy (Ea) in the thermo-catalytic degradation reaction of bovine tallow. The Ea for the thermal degradation of bovine tallow exhibited variations of 178.7 to 199.1 kJ/mol (OFW) and 176.5 to 197.5 kJ/mol (KAS), respectively. In the presence of the MCM-41, Co/MCM-41, Mo/MCM-41, Ni/MCM-41, CoMo/MCM-41, NiMo/MCM-41, and NiCo/MCM-41 catalysts, variations ranged from 143.1 to 156.0, 146.9 to 165.2, 142.5 to 151.7, 145.5 to 165.9, 161.4 to 166.0, 171.8 to 180.4, and 148.2 to 170.0 kJ/mol for the OFW model, respectively. For the KAS model, the variations were 139.0 to 152.2, 143.0 to 162.0, 138.4 to 147.8, 134.7 to 154.7, 158.1 to 163.3, 169.2 to 177.4, and 144.4 to 167.0 kJ/mol, respectively. Among the catalysts used in the kinetic study, Mo/MCM-41 stood out, exhibiting a reduction of approximately 24% in Ea for the raw material according to the OFW model and about 25% according to the KAS model. Both models used yielded satisfactory results, with R2 values above 0.95, confirming the reliability of the methods. These results were pivotal in obtaining parameters for thermo-catalytic pyrolysis. The thermal pyrolysis reaction of bovine tallow generated a high percentage of hydrocarbons (31.76%). However, this percentage increased with the addition of catalysts to the reaction process. Thus, thermo-catalytic pyrolysis of bovine tallow produced 32.71% hydrocarbons using MCM-41, 76.18% with Ni/MCM-41, 43.72% with Mo/MCM-41, 57.86% with Co/MCM-41, 63.55% with NiMo/MCM-41, 74.60% with CoMo/MCM-41, and 84.99% with NiCo/MCM-41. Based on the percentage of hydrocarbons formed in thermal pyrolysis, the production was found to be 52.17% in the aviation bio-kerosene range, 70.40% in the green diesel range, and 14.64% of hydrocarbons with chains above C24. On the other hand, thermo-catalytic pyrolysis favored deoxygenation through decarboxylation, resulting in an even greater percentage of hydrocarbons, particularly in the green diesel range. The use of MCM-41, Ni/MCM-41, Mo/MCM-41, Co/MCM-41, NiMo/MCM-41, CoMo/MCM-41, and NiCo/MCM-41 catalysts yielded, respectively, 51.02%, 34.00%, 38.63%, 42.81%, 32.49%, 36.80%, and 40.03% in the aviation bio-kerosene range and 87.94%, 88.56%, 83.03%, 90.55%, 98.44%, 95.67%, and 93.27% in the green diesel range. Therefore, catalytic pyrolysis of bovine tallow presents itself as a promising alternative for bio-oil production, with a high production of hydrocarbons instead of oxygenated compounds, thus remaining a significant raw material in biofuel production and minimizing environmental impacts arising from its generation through the use of catalysts impregnated with metallic oxides.

COMMITTEE MEMBERS:
Presidente - 2140818 - AMANDA DUARTE GONDIM
Interno - 2087667 - TIAGO PINHEIRO BRAGA
Externo à Instituição - PEDRO NOTHAFT ROMANO - UFRJ
Externa à Instituição - EDJANE FABIULA BURITI DA SILVA - Estácio
Externo à Instituição - FELIPE FERNANDES BARBOSA - UFRN
Externa à Instituição - NATALY ALBUQUERQUE DOS SANTOS - UFPB